Heading in to December 7 meeting in Vienna, Nigerian Petroleum Minister Ibe Kachikwu told reporters he was "hopeful" the nations would be able to reach an agreement.

Ahead of the meeting Brent, the international standard, was down 59 cents at $59.47 a barrel while benchmark New York crude was 61 cents lower at $50.88. Oil prices have fallen about 25 percent in recent months.